Implantable medical devices, including cardiac rhythm management devices such as pacemakers and implantable cardioverter/defibrillators, usually have the capability to communicate data with a device called an external programmer via a radio frequency telemetry link.
The traditional implantable medical device exchanges data with a remote programmer by means of an inductive telemetry coil or other short range communications channel. A hand held wand is positioned within several inches of the implantable device and the data is transferred by an inductive coupling.
With the advent of long range telemetry of messages, and the associated increase in communication range, the risk that a message can be compromised is increased. For example, a replay attack can be launched in which a message, or a piece of a message, can be captured and then maliciously used at a later time.
What is needed are systems and methods for improved telemetry.